A Minnesota state lawmaker and her husband was shot and killed in their home early on Saturday morning in what Governor Tim Walz called a "act of targeted political violence".
Walz said House Speaker Emerita Melissa Hortman, a Democrat, and her husband were killed.
State Senator John Hoffman, also a Democrat, and his wife were targeted in their home as well. They were shot multiple times and are out of surgery, Walz said at a news conference.
Walz said the targeted shootings occurred in Brooklyn Park and Champlin, neighbouring cities to Minneapolis.
Brooklyn Park Police Department has issued a shelter-in-place order for a three-mile (4.8 km) radius of Edinburgh Golf Course.
Zach Lindstrom, the mayor of nearby Mounds View, said elected officials had received a "safety alert".
Authorities are warning people in the area not to answer their door for a police officer unless there are two officers together, local outlet Fox 9 reported.
Mayor Lindstrom said on X that he had heard the suspect was someone impersonating an "officer and they haven't been caught".
Walz said on X that authorities are "monitoring the situation closely" and he has activated a State Emergency Operations Center - used for managing disasters or emergencies.